Limiting water use is needed, with current water takes on the Heretaunga plains acting as "death by 1000 cuts".
The Hawke's Bay Regional Council has signalled a possible ban on new water allocation from the Heretaunga Aquifer, as new science has shown the volume of water being taken was at the "limit of what is environmentally acceptable".
Now, the council's chair Rex Graham has said he would like to see all water users saving 10 per cent of their normal usage within the next two years, to ensure that development on the Heretaunga Plains can continue.
"We don't want to force people to save on water, but we will. Everyone's going to have to get a new mindset on how they use water. It is not an unlimited resource.
"I want everyone to take a really good look at themselves and say how do they use water because it is taonga...and we need to respect it a whole lot more than we do."
This "saving" would apply to all users - from residents, to farmers, and growers.
"We've all come out of an environment where we thought we had an unlimited supply of water, but we don't and we're going to have to get used to a new environment."
Water drawn from the Heretaunga aquifer services the water supply for Hastings and Napier, as well as various business, and industries across these areas.
Mr Graham said he was "not going to stop economic development on the Heretaunga plains because a whole lot of people are mis-using water."
"We all need to take a good look at ourselves and say, 'can't we do this better, because we do need to continue to develop the Heretaunga plains'. We need to have growth."
Limiting water use was discussed at a council regional planning committee meeting this week, when principal scientist hydrology Dr Jeff Smith gave an update on the science conducted by the TANK group, which showed the impact these takes were having.
Although the effect of each individual take might be small, "what we're looking at is death by 1000 cuts".
Pumping had been increasing for the past 30 years, which meant groundwater levels and spring flows in the Heretaunga aquifer system had declined.
Looking at 10 year averages the science showed that municipal water supply takes had been fairly static, as had industrial takes.
Water takes for irrigation, however, had been increasing by about 10million cubic metres every ten years.
Using these averages they found that by 2040 the Mangateretere stream would be going dry in summer, with the Ngaruroro going dry in summer in about 30 years time.
At this stage Dr Smith said the situation was not "catastrophic by any means", but it was time for the council to think about how the resource would be managed in future.
Napier councillor Paul Bailey questioned if council had to consider a limit for growth of water use on the Heretaunga Plains.
He asked whether "we've basically reached the limit with the amount of water take we can have on the Heretaunga plain".
"Regardless of whether we...put a dam in, augment it, whatever. We just cannot keep on growing the amount of water take for water that's not there,"
Currently there is more water "allocated on paper than is used", council resource management group manager Iain Maxwell said.
"Very soon you're going to have put in front of you some hard decisions to make about setting limits, because you have to by law in the NPS and you have to reflect that in your regional plan."
Hastings councillor Rick Barker said this would be a "challenging conversation" for the community.
"We're all used to being able to turn the tap on and use as much water as you like. We're being told here, you can no longer do that.
"What's worse, you're not going to be able to do that in the future."
